/*******************************************************************************
 jquery.mb.components
 copyright (c) 2001-2010. matteo bicocchi (pupunzi); open lab srl, firenze - italy
 email: info@pupunzi.com
 site: http://pupunzi.com

 licences: mit, gpl
 http://www.opensource.org/licenses/mit-license.php
 http://www.gnu.org/licenses/gpl.html
 ******************************************************************************/

/**
* hoverintent is similar to jquery's built-in "hover" function except that
* instead of firing the onmouseover event immediately, hoverintent checks
* to see if the user's mouse has slowed down (beneath the sensitivity
* threshold) before firing the onmouseover event.
* 
* hoverintent r5 // 2007.03.27 // jquery 1.1.2+
* <http://cherne.net/brian/resources/jquery.hoverintent.html>
* 
* hoverintent is currently available for use in all personal or commercial 
* projects under both mit and gpl licenses. this means that you can choose 
* the license that best suits your project, and use it accordingly.
* 
* // basic usage (just like .hover) receives onmouseover and onmouseout functions
* $("ul li").hoverintent( shownav , hidenav );
* 
* // advanced usage receives configuration object only
* $("ul li").hoverintent({
*	sensitivity: 7, // number = sensitivity threshold (must be 1 or higher)
*	interval: 100,   // number = milliseconds of polling interval
*	over: shownav,  // function = onmouseover callback (required)
*	timeout: 0,   // number = milliseconds delay before onmouseout function call
*	out: hidenav    // function = onmouseout callback (required)
* });
* 
* @param  f  onmouseover function || an object with configuration options
* @param  g  onmouseout function  || nothing (use configuration options object)
* @author    brian cherne <brian@cherne.net>
*/
(function($) {
	$.fn.hoverintent = function(f,g) {
		// default configuration options
		var cfg = {
			sensitivity: 7,
			interval: 100,
			timeout: 0
		};
		// override configuration options with user supplied object
		cfg = $.extend(cfg, g ? { over: f, out: g } : f );

		// instantiate variables
		// cx, cy = current x and y position of mouse, updated by mousemove event
		// px, py = previous x and y position of mouse, set by mouseover and polling interval
		var cx, cy, px, py;

		// a private function for getting mouse position
		var track = function(ev) {
			cx = ev.pagex;
			cy = ev.pagey;
		};

		// a private function for comparing current and previous mouse position
		var compare = function(ev,ob) {
			ob.hoverintent_t = cleartimeout(ob.hoverintent_t);
			// compare mouse positions to see if they've crossed the threshold
			if ( ( math.abs(px-cx) + math.abs(py-cy) ) < cfg.sensitivity ) {
				$(ob).unbind("mousemove",track);
				// set hoverintent state to true (so mouseout can be called)
				ob.hoverintent_s = 1;
				return cfg.over.apply(ob,[ev]);
			} else {
				// set previous coordinates for next time
				px = cx; py = cy;
				// use self-calling timeout, guarantees intervals are spaced out properly (avoids javascript timer bugs)
				ob.hoverintent_t = settimeout( function(){compare(ev, ob);} , cfg.interval );
			}
		};

		// a private function for delaying the mouseout function
		var delay = function(ev,ob) {
			ob.hoverintent_t = cleartimeout(ob.hoverintent_t);
			ob.hoverintent_s = 0;
			return cfg.out.apply(ob,[ev]);
		};

		// a private function for handling mouse 'hovering'
		var handlehover = function(e) {
			// next three lines copied from jquery.hover, ignore children onmouseover/onmouseout
			var p = (e.type == "mouseover" ? e.fromelement : e.toelement) || e.relatedtarget;
			while ( p && p != this ) { try { p = p.parentnode; } catch(e) { p = this; } }
			if ( p == this ) { return false; }

			// copy objects to be passed into t (required for event object to be passed in ie)
			var ev = jquery.extend({},e);
			var ob = this;

			// cancel hoverintent timer if it exists
			if (ob.hoverintent_t) { ob.hoverintent_t = cleartimeout(ob.hoverintent_t); }

			// else e.type == "onmouseover"
			if (e.type == "mouseover") {
				// set "previous" x and y position based on initial entry point
				px = ev.pagex; py = ev.pagey;
				// update "current" x and y position based on mousemove
				$(ob).bind("mousemove",track);
				// start polling interval (self-calling timeout) to compare mouse coordinates over time
				if (ob.hoverintent_s != 1) { ob.hoverintent_t = settimeout( function(){compare(ev,ob);} , cfg.interval );}

			// else e.type == "onmouseout"
			} else {
				// unbind expensive mousemove event
				$(ob).unbind("mousemove",track);
				// if hoverintent state is true, then call the mouseout function after the specified delay
				if (ob.hoverintent_s == 1) { ob.hoverintent_t = settimeout( function(){delay(ev,ob);} , cfg.timeout );}
			}
		};

		// bind the function to the two event listeners
		return this.mouseover(handlehover).mouseout(handlehover);
	};
})(jquery);